Chemical and biological characterization of sulfated chitosan oligomer as heparin mimics

In the present study, chitosan oligomer was modified to sulfated chitosan oligomer (ShCsO) to mimic heparin. Its chemical structure was determined by infrared spectroscopy (FT-IR), X-ray diffractometry (XRD), differential scanning calorimetry (DSC), and thermogravimetric analysis. The results showed that the FT-IR spectrum band at 799 cm−1 corresponds to C–O–S and that at 1212 cm−1 corresponds to S=O bond stretching, which prove that the sulfate groups are incorporated into chitosan oligomer successfully. The antimicrobial activity of ShCsO against to Bacillus subtilis in 1% concentration was 89.1 ± 1.7% . The IC50 (μg/ml) of ShCsO was 67.75, 56.07, 85.47, and 84.68 for A2780, MCF-7, DU-145, and HepG2, respectively. The results show that this newly synthesized material is a potential candidate to heparin-like chitosan derivatives. According to the literature, it was the first time that chitosan oligomer was modified to mimic heparin.

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Thermal Behaviour of Candesartan Active substance and in pharmaceutical compounds

Revista de Chimie ◽

10.37358/rc.17.8.5787 ◽

2017 ◽

Vol 68 (8) ◽

pp. 1895-1902

Author(s):

Ioana Cristina Tita ◽

Eleonora Marian ◽

Bogdan Tita ◽

Claudia Crina Toma ◽

Laura Vicas

Keyword(s):

Thermal Behaviour ◽

Active Substance ◽

Pharmaceutical Research ◽

Pharmaceutical Product ◽

Nitrogen Atmosphere ◽

Pure Substance ◽

Scanning Calorimetry ◽

X Ray ◽

Ft Ir

Thermal analysis is one of the most frequently used instrumental techniques in the pharmaceutical research, for the thermal characterization of different materials from solids to semi-solids, which are of pharmaceutical relevance. In this paper, simultaneous thermogravimetry/derivative thermogravimetry (TG/DTG) and differential scanning calorimetry (DSC) were used for characterization of the thermal behaviour of candesartan cilexetil � active substance (C-AS) under dynamic nitrogen atmosphere and nonisothermal conditions, in comparison with pharmaceutical product containing the corresponding active substance. It was observed that the commercial samples showed a different thermal profile than the standard sample, caused by the presence of excipients in the pharmaceutical product and to possible interaction of these with the active substance. The Fourier transformed infrared spectroscopy (FT-IR) and X-ray powder diffraction (XRPD) were used as complementary techniques adequately implement and assist in interpretation of the thermal results. The main conclusion of this comparative study was that the TG/DTG and DSC curves, together with the FT-IR spectra, respectively X-ray difractograms constitute believe data for the discrimination between the pure substance and pharmaceutical forms.

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Characterization of SrBi2Nb2O9 Thin Films Prepared by Sol Gel Technique

MRS Proceedings ◽

10.1557/proc-459-213 ◽

1996 ◽

Vol 459 ◽

Cited By ~ 7

Author(s):

E. Ching-Prado ◽

W. Pérez ◽

A. Reynés-Figueroa ◽

R. S. Katiyar ◽

D. Ravichandran ◽

...

Keyword(s):

Thin Films ◽

Raman Band ◽

Sol Gel ◽

Orthorhombic Symmetry ◽

X Ray Diffraction ◽

Ft Ir ◽

Gel Technique ◽

High Degree ◽

First Time

ABSTRACTThin films of SrBi2Nb2O9 (SBN) with thicknesses of 0.1, 0.2, and 0.4 μ were grown by Sol-gel technique on silicon, and annealed at 650°C. The SBN films were investigated by Raman scatering for the first time. Raman spectra in some of the samples present bands around 60, 167, 196, 222, 302, 451, 560, 771, 837, and 863 cm−1, which correspond to the SBN formation. The study indicates that the films are inhomogeneous, and only in samples with thicknesses 0.4 μ the SBN material was found in some places. The prominent Raman band around 870 cm−1, which is the A1g mode of the orthorhombic symmetry, is assigned to the symmetric stretching of the NbO6 octahedrals. The frequency of this band is found to shift in different places in the same sample, as well as from sample to sample. The frequency shifts and the width of the Raman bands are discussed in term of ions in non-equilibrium positions. FT-IR spectra reveal a sharp peak at 1260 cm−1, and two broad bands around 995 and 772 cm−1. The bandwidths of the latter two bands are believed to be associated with the presence of a high degree of defects in the films. The experimental results of the SBN films are compared with those obtained in SBT (T=Ta) films. X-ray diffraction and SEM techniques are also used for the structural characterization.

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THE PHYSICOCHEMICAL CHARACTERISTICS OF RECYCLED-PLASTIC PELLETS OBTAINED FROM DISPOSABLE FACE MASK WASTES

Jurnal Sains Materi Indonesia ◽

10.17146/jsmi.2021.23.1.6336 ◽

2021 ◽

Vol 23 (1) ◽

pp. 16

Author(s):

Vienna Saraswaty ◽

Rossy Choerun Nissa ◽

Bonita Firdiana ◽

Akbar Hanif Dawam Abdullah

Keyword(s):

Tensile Strength ◽

Physicochemical Characterization ◽

Face Mask ◽

Physicochemical Characteristics ◽

Scanning Calorimetry ◽

Elongation At Break ◽

Ft Ir ◽

The Government ◽

Plastic Pellets

THE PHYSICOCHEMICAL CHARACTERISTICS OF RECYCLED-PLASTIC PELLETS OBTAINED FROM DISPOSABLE FACE MASK WASTES. The government policy to wear a face mask during the COVID-19 pandemic has increased disposable face mask wastes. Thus, to reduce such wastes, it is necessary to evaluate the physicochemical characteristics of disposable face masks wastes before the recycling process and the recycled products. In this study, physicochemical characterization of the 3-ply disposable face masks and the recycled plastic pellets after disinfection using 0.5% v/v sodium hypochlorite were evaluated. A set of parameters including the characterization of surface morphology by a scanning electron microscope (SEM), functional groups properties by a fourier transform infra-red spectroscopy (FT-IR), thermal behavior by a differential scanning calorimetry (DSC), tensile strength and elongation at break were evaluated. The surface morphological of each layer 3-ply disposable face mask showed that the layers were composed of non-woven fibers. The FT-IR evaluation revealed that 3-ply disposable face mask was made from a polypropylene. At the same time, the DSC analysis found that the polypropylene was in the form of homopolymer. The SEM analysis showed that the recycled plastic pellets showed a rough and uneven surface. The FT-IR, tensile strength and elongation at break of the recycled plastic pellets showed similarity with a virgin PP type CP442XP and a recycled PP from secondary recycling PP (COPLAST COMPANY). In summary, recycling 3-ply disposable face mask wastes to become plastic pellets is recommended for handling disposable face mask wastes problem.

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Preparation and characterization of oxidized starch-graft-poly(styrene-butyl acrylate) latex via emulsion polymerization

Journal of Polymer Engineering ◽

10.1515/polyeng-2014-0047 ◽

2014 ◽

Vol 34 (7) ◽

pp. 611-616 ◽

Cited By ~ 11

Author(s):

Shijie Cheng ◽

Jun Xu ◽

Yumin Wu

Keyword(s):

Emulsion Polymerization ◽

Butyl Acrylate ◽

Colloidal Stability ◽

Graft Copolymerization ◽

Scanning Calorimetry ◽

Oxidized Starch ◽

Ir Transmission ◽

Ft Ir ◽

Synthetic Latex

Abstract Oxidized starch-graft-poly(styrene-butyl acrylate) [OS-g-P(St-BA)] latex was synthesized by the graft copolymerization of OS with St and n-butyl acrylate (BA) via emulsion polymerization. The graft copolymers were characterized by Fourier transform infrared (FT-IR), transmission electronic microscopy (TEM), dynamic light scattering, thermogravimetry (TG), and differential scanning calorimetry (DSC). The effects of the amount of OS, monomers, and initiator on graft copolymerization were investigated. Under the optimal conditions, the percentage of graft (PG), grafting efficiency (GE), and ζ potential could reach 256.5%, 41.7%, and -30.1 mV, respectively. The results indicated that the OS grafted onto particles greatly enhanced the colloidal stability of latex. The thermal stability properties of OS-g-P(St-BA) were also improved by the addition of OS. The OS-g-P(St-BA) latex may be used to partly replace the conventional synthetic latex for paper coating.

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Formulation and Characterization of Aceclofenac-Loaded Nanofiber Based Orally Dissolving Webs

Pharmaceutics ◽

10.3390/pharmaceutics11080417 ◽

2019 ◽

Vol 11 (8) ◽

pp. 417 ◽

Cited By ~ 12

Author(s):

Emese Sipos ◽

Nóra Kósa ◽

Adrienn Kazsoki ◽

Zoltán-István Szabó ◽

Romána Zelkó

Keyword(s):

Oral Absorption ◽

Vinyl Pyrrolidone ◽

Drug Dissolution ◽

In Vitro Dissolution ◽

Drug Release Profile ◽

Scanning Calorimetry ◽

Ft Ir ◽

Fast Dissolution ◽

Poly Vinyl Pyrrolidone

Aceclofenac-loaded poly(vinyl-pyrrolidone)-based nanofiber formulations were prepared by electrospinning to obtain drug-loaded orally disintegrating webs to enhance the solubility and dissolution rate of the poorly soluble anti-inflammatory active that belongs to the BCS Class-II. Triethanolamine-containing ternary composite of aceclofenac-poly(vinyl-pyrrolidone) nanofibers were formulated to exert the synergistic effect on the drug-dissolution improvement. The composition and the electrospinning parameters were changed to select the fibrous sample of optimum fiber characteristics. To determine the morphology of the nanofibers, scanning electron microscopy was used. Fourier transform infrared spectroscopy (FT-IR), and differential scanning calorimetry (DSC) were applied for the solid-state characterization of the samples, while the drug release profile was followed by the in vitro dissolution test. The nanofibrous formulations had diameters in the range of few hundred nanometers. FT-IR spectra and DSC thermograms indicated the amorphization of aceclofenac, which resulted in a rapid release of the active substance. The characteristics of the selected ternary fiber composition (10 mg/g aceclofenac, 1% w/w triethanolamine, 15% w/w PVPK90) were found to be suitable for obtaining orally dissolving webs of fast dissolution and potential oral absorption.

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Synthesis of V2O3/C composites with different morphologies by a facile route and phase transition properties of the compounds

Materials Science-Poland ◽

10.2478/s13536-013-0177-6 ◽

2014 ◽

Vol 32 (2) ◽

pp. 236-242 ◽

Cited By ~ 7

Author(s):

Yifu Zhang ◽

Nannan Wang ◽

Yuting Huang ◽

Chi Huang ◽

Xiao Mei ◽

...

Keyword(s):

Electron Microscopy ◽

Phase Transition ◽

Hydrothermal Route ◽

Scanning Calorimetry ◽

Transmission Electron ◽

Facile Hydrothermal Route ◽

Potential Applications ◽

Subsequent Calcination ◽

Ft Ir ◽

First Time

AbstractV2O3 and amorphous carbon composites (V2O3/C composites) with different morphologies (e.g. nanospheres, nanorods and nanosheets) were, for the first time, successfully synthesized by a facile hydrothermal route and subsequent calcination. The as-obtained samples were characterized by X-ray powder diffraction (XRD), energy dispersive spectrometery (EDS), elemental analysis (EA), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The morphology of V2O3/C composites could be easily controlled by varying the reaction time, and, as a result, V2O3/C composites with nanospheres, nanorods and nanosheets were selectively synthesized. Furthermore, the phase transition property of V2O3/C composites was measured by differential scanning calorimetry (DSC), suggesting that V2O3/C composites exhibit the phase transition similar to V2O3, which could expand the potential applications of materials related to V2O3 in the future.

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Structural stability of biofilms produced from silkworm cocoon fibers

Journal of the Serbian Chemical Society ◽

10.2298/jsc210611054f ◽

2021 ◽

pp. 54-54

Author(s):

Souza Felício ◽

Henrique Santana

Keyword(s):

Conformational Changes ◽

Casting Process ◽

Scanning Calorimetry ◽

Molecular Conformations ◽

Freeze Dried ◽

Vis Spectroscopy ◽

Ft Ir ◽

Silkworm Cocoon ◽

Band Characteristic

Biofilms were obtained from cocoons of the silkworm, Bombyx mori, involving the removal of sericin, extraction and solubilization of fibroin fibers, dialysis of fibroin dispersions and preparation of biofilms by the casting process. Biofilm transparency was verified by UV-Vis spectroscopy and thermal stability by thermogravimetric/differential scanning calorimetry (TG/DSC). Soon after preparation, the solidification of the fibroin solution prepared from the cocoons and extracted by the Ajisawa method was monitored until the biofilm stabilized, using Attenuated Total Reflectance-Fourier Transform Infrared spectroscopy (ATR FT-IR) as a function of time. The results showed that there is a change in the conformation from the silk I structure (?-helix) to silk II (?-sheet). In order to improve the characterization of the biofilms obtained by the Ajisawa method and LiBr solubilization of fibroin fibers, Raman spectroscopy was used to verify stabilization of the different possible molecular conformations for the fibers in these materials, by comparison with the cocoon spectra and those of the solid (freeze-dried hydrogel) precipitated by dialysis for 72 h. By comparing the Raman spectra of the biofilms in terms of the intensities of the broadened band characteristic of amide I, it was possible to assess the conformational changes in both materials based on possible transitions between ?-sheet conformations and flexible ?-helix and ?-turn structures. The results showed a dispersion of these conformations in the biofilms generated and in the solid freeze-dried hydrogel spectrum, and the ?-sheet conformation was found to be predominant. The TG and DSC curves showed that the materials with higher ?-sheet content exhibited higher thermal resistance. Thus, the data obtained further elucidate the properties of these materials which are widely used in various processes.

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Molecular Characterization, Pathogenicity and Biological Characterization of Colletotrichum Species Associated with Anthracnose of Camellia yuhsienensis Hu in China

Forests ◽

10.3390/f12121712 ◽

2021 ◽

Vol 12 (12) ◽

pp. 1712

Author(s):

Xinggang Chen ◽

Lingyu Jiang ◽

Anhua Bao ◽

Changlin Liu ◽

Junang Liu ◽

...

Keyword(s):

Mycelial Growth ◽

Morphological Characteristics ◽

Biological Characteristics ◽

Camellia Oleifera ◽

Biological Characterization ◽

Pathogenicity Tests ◽

Colletotrichum Spp ◽

And Control ◽

First Time

Camellia yuhsienensis Hu, a species of tea oil tree with resistance to anthracnose, is widely used to breed disease-resistant Camellia varieties. In 2019, anthracnose symptoms were observed on Ca. yuhsienensis for the first time. However, the species and biological characteristics of Colletotrichum spp. isolated from Ca. yuhsienensis (YX-Colletotrichum spp.) have not been elucidated. In this study, five isolates (YX2-5-2, 2YX-3-1, 2YX-5-1, 2YX-8-1-1 and 2YX-8-1-2), which were consistent with the morphological characteristics of Colletotrichum spp., were obtained from Ca. yuhsienensis. A phylogenetic analysis demonstrated that YX2-5-2, 2YX-3-1 and 2YX-8-1-2 belonged to first clade along with Colletotrichum fructicola. 2YX-8-1-1 belonged to the second clade along with Colletotrichum siamense. 2YX-5-1 belonged to the third clade with Colletotrichum camelliae. Pathogenicity tests revealed that the pathogenicity of YX-Colletotrichum spp. was stronger than that of Colletotrichum spp. isolated from Camellia oleifera (GD-Colletotrichum spp.). Biological characteristics illustrated that the mycelial growth of YX-Co. camelliae (2YX-5-1) was slower than that of GD-Co. camelliae when the temperature exceeded 20 °C. In addition, in the presence of ions, the mycelial growth of YX-Co. fructicola (YX2-5-2) and YX-Co. siamense (2YX-8-1-1) was also slower than that of GD-Co. fructicola and GD-Co. siamense. Furthermore, the ability of YX-Colletotrichum spp. to utilize lactose and mannitol was weaker than that of GD-Colletotrichum spp., while the ability to utilize NH4+ was generally stronger than that of GD-Colletotrichum spp. This is the first report of anthracnose of Ca. yuhsienensis induced by Co. fructicola, Co. siamense and Co. camelliae in China. These results will provide theoretical guidance for the study of the pathogenesis and control of anthracnose on Ca. yuhsienensis.

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Synthesis and Spectral Characterization of 4,7-Dichloro-6-nitroquinazoline

Molbank ◽

10.3390/m1134 ◽

2020 ◽

Vol 2020 (2) ◽

pp. M1134 ◽

Cited By ~ 1

Author(s):

Thi Ngoc Nguyen ◽

Thi Huong Tran ◽

Nguyet Suong Huyen Dao ◽

Van Giang Nguyen ◽

Dinh Luyen Nguyen ◽

...

Keyword(s):

Kinase Inhibitor ◽

Therapeutic Potential ◽

Locally Advanced ◽

Intermediate Compound ◽

Chlorobenzoic Acid ◽

Ft Ir ◽

Important Intermediate ◽

Quinazoline Derivatives ◽

First Time

Afatinib is a 4-anilinoquinazoline tyrosine kinase inhibitor (TKI) in the form of a dimaleate salt which is indicated for the treatment of locally advanced or metastatic non-small cell lung cancer (NSCLC). The most scalable route for the synthesis of this drug was reported in two Boehringer Ingelheim patents, in which the title compound, 4,7-dichloro-6-nitroquinazoline (IV), is an important intermediate. Compound IV is also present in a number of synthetic pathways for various 4,7-disubstituted quinazoline derivatives displaying high therapeutic potential. However, no detailed characterization of this popular compound has been reported, possibly due to its high instability. In this paper, IV was prepared in an overall yield of 56.1% by a 3-step process (condensation, nitration, and chlorination) from 2-amino-4-chlorobenzoic acid (I). The target compound has been for the first time fully characterized by melting point, mass-spectrometry, FT-IR, 1H-NMR and 13C-NMR spectroscopies.

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Characterization of the Spindle Morphology Nanomicelles Assembled from Sericin and Gelatin

Journal of Nanomaterials ◽

10.1155/2017/6857637 ◽

2017 ◽

Vol 2017 ◽

pp. 1-9

Author(s):

Xiaozhou Su ◽

Lei Li ◽

Weihan Huang

Keyword(s):

Electron Microscopy ◽

Protein Concentration ◽

Scanning Calorimetry ◽

Force Microscopy ◽

Atomic Force ◽

Transmission Electron ◽

Ft Ir ◽

And Storage ◽

Ft Ir Spectroscopy

Complex nanomicelles were prepared by sericin and type A gelatin with molecular weight of 5789 Da and 128664 Da separately. The assembling conditions were as follows: mass ratio (sericin/gelatin) was 1 : 1, protein concentration was 0.5%, temperature was 35°C, and assembling time was 18 hours. Scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC), and dynamic light scattering (DLS) were conducted to observe and characterize the complex nanomicelles. Results showed that the complex sericin/gelatin micelles was a kind of nanospindle micelles. The micelles had high electrochemical stability, thermal stability, antidilution stability, and storage stability.

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